In the medical field, it has been widely practiced to apply radiation from a radiation source to a subject and detect the radiation that has passed through the subject with a radiation detecting device thereby to acquire a radiographic image of the subject (see, for example, Japanese Laid-Open Patent Publication No. 2006-140592).
Radiation detecting devices are roughly classified into indirect conversion radiation detecting devices which include a scintillator or the like for converting radiation into visible light and a photodiode or the like for converting the visible light into electric charges, and direct conversion radiation detecting devices which have a semiconductor material for directly absorbing and converting radiation into electric charges.
In a case where the above radiation detecting devices are used in high-speed moving image capturing processes such as fluorography and digital subtraction angiography (DSA) or the like, they may cause artifacts or afterimages due to the response of a phosphor (fluorophore) or a photoelectric transducer device, lowering the quality of generated images, immediately after X-rays of high dose are applied at one period of time or continuously.
One known solution to such afterimages is disclosed as an X-ray detector in Japanese Patent No. 4150079, for example. The X-ray detector disclosed in Japanese Patent No. 4150079 has a bias radiation source for irradiating a semiconductor device with an electromagnetic radiation thereby to prevent afterimages from being produced without complex corrective calculations. Specifically, it is known that it is effective to remove afterimages to apply resetting light to a photoelectric transducing portion, i.e., to reset the photoelectric transducing portion with light, which converts fluorescence generated by a scintillator into an electric signal.